Browsing by Author "Ge, Liehui"

Now showing 1 - 3 of 3
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    Bifunctional Luminomagnetic Rare-Earth Nanorods for High-Contrast Bioimaging Nanoprobes
    (Springer Nature, 2016) Gupta, Bipin Kumar; Singh, Satbir; Kumar, Pawan; Lee, Yean; Kedawat, Garima; Narayanan, Tharangattu N.; Vithayathil, Sajna Antony; Ge, Liehui; Zhan, Xiaobo; Gupta, Sarika; Martí, Angel A.; Vajtai, Robert; Ajayan, Pulickel M.; Kaipparettu, Benny Abraham
    Nanoparticles exhibiting both magnetic and luminescent properties are need of the hour for many biological applications. A single compound exhibiting this combination of properties is uncommon. Herein, we report a strategy to synthesize a bifunctional luminomagnetic Gd2−xEuxO3 (x = 0.05 to 0.5) nanorod, with a diameter of ~20 nm and length in ~0.6 μm, using hydrothermal method. Gd2O3:Eu3+ nanorods have been characterized by studying its structural, optical and magnetic properties. The advantage offered by photoluminescent imaging with Gd2O3:Eu3+ nanorods is that this ultrafine nanorod material exhibits hypersensitive intense red emission (610 nm) with good brightness (quantum yield more than 90%), which is an essential parameter for high-contrast bioimaging, especially for overcoming auto fluorescent background. The utility of luminomagnetic nanorods for biological applications in high-contrast cell imaging capability and cell toxicity to image two human breast cancer cell lines T47D and MDA-MB-231 are also evaluated. Additionally, to understand the significance of shape of the nanostructure, the photoluminescence and paramagnetic characteristic of Gd2O3:Eu3+ nanorods were compared with the spherical nanoparticles of Gd2O3:Eu3+.
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    Charge coupled device based on atomically layered van der waals solid state film for opto-electronic memory and image capture
    (2016-08-30) Lei, Sidong; Ge, Liehui; George, Antony; Li, Bo; Vajtai, Robert; Ajayan, Pulickel M.; Rice University; United States Patent and Trademark Office
    An opto-electronic sensor may provide one or more layers of atomically layered photo-sensitive materials. The sensor may include a gate electrode layer, a dielectric layer in contact with the gate electrode layer, and a working media layer that is photo-sensitive deposited on the dielectric layer. The working media layer may provide one or more layers of one or more materials where each of the one or more layers is an atomic layer. The sensor may also include side electrodes in contact with the working media layer.
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    Ternary CuIn7Se11: Towards Ultra-Thin Layered Photodetectors and Photovoltaic Devices
    (Wiley, 2014) Lei, Sidong; Sobhani, Ali; Wen, Fangfang; George, Antony; Wang, Qizhong; Huang, Yihan; Dong, Pei; Li, Bo; Najmaei, Sina; Bellah, James; Gupta, Gautam; Mohite, Aditya D.; Ge, Liehui; Lou, Jun; Halas, Naomi J.; Vajtai, Robert; Ajayan, Pulickel
    2D materials have been widely studied over the past decade for their potential applications in electronics and optoelectronics. In these materials, elemental composition plays a critical role in defining their physical properties. Here we report the first successful synthesis of individual high quality CuIn7Se11 (CIS) ternary 2D layers and demonstrate their potential use in photodetection applications. Photoconductivity measurements show an indirect bandgap of 1.1 eV for few-layered CIS, an external quantum efficiency of 88.0 % with 2 V bias across 2 μm channel with and a signal-to-noise ratio larger than 95 dB. By judicious choice of electrode materials, we demonstrate the possibility of layered CIS-based 2D photovoltaic devices. This study examines this ternary 2D layered system for the first time, demonstrating the clear potential for layered CIS in 2D material-based optoelectronic device applications.